I hate that I only learned about this amino acid recently. I haven't been using for very long but it has been AMAZING for my severe insomnia (which is what I purchased for to try), my anxiety, and general mood. I've taken the recommended dose about an hour before bed and can now actually SLEEP at night. Literally the only issue I have with it is the short half life (approx. 4 hours) so I have woken up in the middle of the night a few times but I'm experimenting with other additions to prevent waking. HOWEVER, I can't tell you how wonderful it is to go to bed at 11pm, actually be able to fall asleep, and then wake up around 3am-4am and have actually slept in that time, it's life changing for me. The times I have woken up I've been able to fall back asleep without a problem. In the morning I experience zero grogginess and am actually ready to face the day. So much gratitude to Double Wood for providing this high quality L-Serine!